Effects of anaesthetic agents and relaxants on vascular tone studies in Sandison Clark chambers.

T H E effects on blood vessels of drugs commonly used in anaesthesia are of great interest to the clinician whose constant aim is to produce minimal physiological side effects during anaesthesia. A previous investigation using the Sandison Clark "regenerated" type chamber on the rabbit ear has been reported (Seldon et al., 1942). The present research has been carried out with the "preformed" ear chamber and in some cases the results differ from this earlier report. In the preformed chamber the blood vessels under observation are the original subcutaneous vessels of the rabbit ear; in the regenerated type the blood vessels are the vessels formed in the process of repair. It would appear more satisfactory to assess the effects of anaesthetic agents on the normally innervated vessels of the animal and not in those of the repair blastoma.